It is frequently desirable or necessary to connect a variety of electrically powered components to existing electrical systems of an automotive vehicle. These may include air horns, alarms systems which may utilize flashing lights or the like, amplifiers, cooling fans or sound amplifiers, power antennae, fog lights, neon lights and the like.
In the past the connection of such units has been generally effected manually and has been fraught with problems. For example, when flashers had to be provided, they normally were sensitive to the incursion of moisture and produced interference which could affect the radio or sound systems. Furthermore, the flashers changed frequencies depending upon load, or would not operate if not connected to a significant load.
When remote controls were used with earlier systems, they frequently had insufficient power to operate the power amplifier of the sound system. Special precautions had to be taken when wiring flashing components and amplifiers into the system and, since wiring had to be done individually or each component added, comparatively problems frequently were not addressed.
In addition, if the wiring was not done by professionally qualified personnel, problems were encountered with the installed components as well as with factory-installed or original equipment.
The problems were particularly pronounced for cars with alarm systems or on which air horns had to be added.